If there is lying for a long time to stand up black in front of the eyes, mostly because of upright hypotension and caused by. Lie too long, the blood volume in the human body is insufficient, once stood up resulting in insufficient blood supply to the brain, will produce the situation of blackness in front of the eyes, and even serious people may produce fainting, shock. Once this happens, you need to immediately lie down and rest, and call your family or friends to call 120. in addition, you can drink brown sugar water to regulate, and if possible, you can breathe oxygen and wait for the arrival of 120 medical staff. After arriving at the hospital, perform relevant tests to rule out other causes of hypotension. Measure the blood pressure, and if it is not corrected, take blood pressure boosting drugs such as ephedrine and dopamine combination, etc.